The invention relates to moisture protection materials and, in particular, to a multicomponent through-wall flashing material containing copper sheet substrate laminated with fiberglass and waterbased adhesives.
Through wall flashing defines a membrane used in the construction of a masonary wall for the purpose of collecting any infiltrating moisture and directing that moisture out of the wall rather than the moisture progressing further into the wall interior of the building causing costly damage. Moistureproofing materials containing copper as a substrate are well known for use as through-wall flashings to permanently protect structures commonly found in the construction industry from unwanted water penetration. Copper is a desirable membrane material for through-wall applications because of its high degree of resistance to deterioration in the corrosive moist and alkaline atmosphere generally found in construction using motar such as unit masonary where there is a need for protection. Copper also has the desired properties of high tensile strength and good puncture resistance needed to withstand high compressive loads in through-wall applications.
Previously, in conventional laminated through-wall flashings used to control moisture in structures, copper sheeting was laminated with asphalt, fabric, paper, elastomeric liquid materials in liquid or solid form such as urethanes, silicone, siloxanes and silanes. However, there are problems associated with some of these laminations. Asphalt is difficult to work with since it must be applied to the substrate at a very high temperature of about 400 degrees F. and it results in a heavy coating which becomes stiff and rigid and not flexible at low temperatures. The excessive thickness causes installation difficulties where a normal thin motar joint is required. Further, asphalt, fabric and paper are capable of burning and in some cases the fumes can cause injury. Also, some of these flashings cause problems by being susceptible to mildew and rotting. Additionally, the conventional through-wall flashings with exposed asphalt surfaces are generally incompatible with sealant materials generally used to prevent moisture penetration at the termination of the flashing.
In conventional laminated through-wall flashings, the copper sheeting thicknesses generally are between one ounce and seven ounces per squre foot. This relatively light weight copper has been successfully used. However, the lighter the copper sheeting, the more it must be protected by thicker and heavier lamination in order to protect it from puncture, abrasion, and scuffing at the time of installation.
There is a need for an improved laminated light weight copper flashing having excellent moistureproofing properties which overcome the deficiencies of prior art copper flashings.
In accordance with the the present invention, it has been found that many of the advantages of the prior art copper flashings have been obtained and many of the deficiencies eliminated by utilizing multicomponent copper flashings laminated on at least one side with fiberglass sheeting and waterbased adhesives. The weight of copper sheeting used can be one to ten ounces per square foot preferably of two, three, five and seven ounces per square foot, to provide a lightweight, durable copper flashing bonded with the textured glass fabric and the waterbased adhesive layer as required.
The fiberglass sheeting is made with glass fabric which is stronger and more resistant to the elements than prior art products incorporating cotton fabric. The fiberglass cloth is used for added strength for puncture and tear resistance. Also, the rough exposed fiberglass cloth texture provides a tooth for increased bond with the motar used in brick construction and bonds mechanically making a stronger, more stable wall.
The preferred water based adhesives used are water based polyvinyl emulsion or ethylene vinyl acetate emulsion adhesives. Using these water based adhesives in the laminated flashings provides improvements over the prior art both in the manufacturing process and in the laminated flashing products. One significant improvement as opposed to the prior art is, that since the adhesive is liquid at room temperature, it simplifies the manufacturing process by being able to be applied by a number of procedures, such as, by spraying, roll contact coating, immersion coating or being applied by brushing. A preferred application is by being able to spray a thin emulsion coating of the of the waterbased adhesive on the fiberglass sheeting and thereby securely bonding the fiberglass sheeting to the copper sheeting substrate and protecting the entire flashing by means of this thin adhesive coating. A further significant improvement is, that after application, the adhesive coated flashing can be dried and cured quickly at room temperature with or without added energy input, such as, fans, heating, cooling, etc., as opposed to prior art high temperature processes or other energy assisted techniques. Another significant improvement is that the quantity of the water based adhesive coating for good quality laminations between the metal foil and the fiberglass is at least eighty percent less than prior art asphalt coatings and far less thickness of the adhesive coating than other adhesives being used such as foam layer adhesives. Further, the present water based adhesives are non-toxic both in the liquid/uncured state and in the dry/cured state. Additionally, the present water based adhesive can be cleaned with water as opposed to use of harmful solvents for other prior art materials. Also, the present flashings can be provided in bulk rolls and subsequently rerolled and split in width as required. The thickness of the adhesive coatings on the prepared flashings are thinner and more flexible. Because of the thinner coating and the elasticity the present flashings are more flexible and workable at very low temperatures. This makes it easier to install under a wide variety of atmospheric conditions. The adhesive coating remains flexible, workable and will not delaminate at any temperature likely to be encountered during the construction of a building from about minus twenty degrees F. to about one hundred and fifty degrees F. as opposed to many previous adhesive coatings which become brittle at lower temperatures.